摘要:
Micro check valves having a free-floating member for controlling flow of fluid in microfluidic and biomedical applications and methods of fabrication. A micro check valve includes a valve seat, a valve cap that contacts the valve seat and an untethered floating member that can move between the valve seat and the valve cap. Certain micro check valves have zero cracking pressure and no reverse leakage. Certain other valves may be configured to permit flow of fluid within a pressure range. The floating member can be solid or define an orifice, and the valve seat can have one or two levels. Valves can be configured to allow fluid to flow when the floating member is pushed by fluid against the valve cap or against the valve seat. The valve seat may be silicon or another material that is compatible with micromachining processes, and the valve cap and the floating member may be a polymer such as Parylene.
摘要:
A variable capacitor, a microfabricated implantable pressure sensor including a variable capacitor and an inductor, and related pressure measurement and implantation methods. The inductor may have a fixed or variable inductance. A variable capacitor and pressure sensors include a flexible member that is disposed on a substrate and defines a chamber. Capacitor elements extend indirectly from the flexible member. Sufficient fluidic pressure applied to an exterior surface of the flexible member causes the flexible member to move or deform, thus causing the capacitance and/or inductance to change. Resulting changes in resonant frequency or impedance can be detected to determine pressure, e.g., intraocular pressure.
摘要:
A variable capacitor, a microfabricated implantable pressure sensor including a variable capacitor and an inductor, and related pressure measurement and implantation methods. The inductor may have a fixed or variable inductance. A variable capacitor and pressure sensors include a flexible member that is disposed on a substrate and defines a chamber. Capacitor elements extend indirectly from the flexible member. Sufficient fluidic pressure applied to an exterior surface of the flexible member causes the flexible member to move or deform, thus causing the capacitance and/or inductance to change. Resulting changes in resonant frequency or impedance can be detected to determine pressure, e.g., intraocular pressure.
摘要:
A variable capacitor, a microfabricated implantable pressure sensor including a variable capacitor and an inductor, and related pressure measurement and implantation methods. The inductor may have a fixed or variable inductance. A variable capacitor and pressure sensors include a flexible member that is disposed on a substrate and defines a chamber. Capacitor elements extend indirectly from the flexible member. Sufficient fluidic pressure applied to an exterior surface of the flexible member causes the flexible member to move or deform, thus causing the capacitance and/or inductance to change. Resulting changes in resonant frequency or impedance can be detected to determine pressure, e.g., intraocular pressure.
摘要:
A variable capacitor, a microfabricated implantable pressure sensor including a variable capacitor and an inductor, and related pressure measurement and implantation methods. The inductor may have a fixed or variable inductance. A variable capacitor and pressure sensors include a flexible member that is disposed on a substrate and defines a chamber. Capacitor elements extend indirectly from the flexible member. Sufficient fluidic pressure applied to an exterior surface of the flexible member causes the flexible member to move or deform, thus causing the capacitance and/or inductance to change. Resulting changes in resonant frequency or impedance can be detected to determine pressure, e.g., intraocular pressure.
摘要:
Micro check valves having a free-floating member for controlling flow of fluid in microfluidic and biomedical applications and methods of fabrication. A micro check valve includes a valve seat, a valve cap that contacts the valve seat and an untethered floating member that can move between the valve seat and the valve cap. Certain micro check valves have zero cracking pressure and no reverse leakage. Certain other valves may be configured to permit flow of fluid within a pressure range. The floating member can be solid or define an orifice, and the valve seat can have one or two levels. Valves can be configured to allow fluid to flow when the floating member is pushed by fluid against the valve cap or against the valve seat. The valve seat may be silicon or another material that is compatible with micromachining processes, and the valve cap and the floating member may be a polymer such as Parylene.
摘要:
An implanted parylene tube shunt relieves intra-ocular pressure. The device is implanted with an open end in the anterior chamber of the eye, allowing excess fluid to be drained through the tube out of the eye. In one embodiment, only a first end of the tube implanted into the anterior chamber of the eye is open. Intra-ocular pressure (IOP) is then monitored, for example utilizing an implanted sensor. When IOP exceeds a critical valve, a practitioner intervenes, puncturing with a laser a thinned region of the tube lying outside the eye, thereby initiating drainage of fluid and relieving pressure. In accordance with alternative embodiments, the both ends of the tube are open, and the tube includes a one-way valve configured to permit drainage where IOP exceeds the critical value. The tube may include projecting barbs to anchor the tube in the eye without the need for sutures.
摘要:
An implanted parylene tube shunt relieves intra-ocular pressure. The device is implanted with an open end in the anterior chamber of the eye, allowing excess fluid to be drained through the tube out of the eye. In one embodiment, only a first end of the tube implanted into the anterior chamber of the eye is open. Intra-ocular pressure (IOP) is then monitored, for example utilizing an implanted sensor. When IOP exceeds a critical valve, a practitioner intervenes, puncturing with a laser a thinned region of the tube lying outside the eye, thereby initiating drainage of fluid and relieving pressure. In accordance with alternative embodiments, the both ends of the tube are open, and the tube includes a one-way valve configured to permit drainage where IOP exceeds the critical value. The tube may include projecting barbs to anchor the tube in the eye without the need for sutures.
摘要:
Micro check valves having a free-floating member for controlling flow of fluid in microfluidic and biomedical applications and methods of fabrication. A micro check valve includes a valve seat, a valve cap that contacts the valve seat and an untethered floating member that can move between the valve seat and the valve cap. Certain micro check valves have zero cracking pressure and no reverse leakage. Certain other valves may be configured to permit flow of fluid within a pressure range. The floating member can be solid or define an orifice, and the valve seat can have one or two levels. Valves can be configured to allow fluid to flow when the floating member is pushed by fluid against the valve cap or against the valve seat. The valve seat may be silicon or another material that is compatible with micromachining processes, and the valve cap and the floating member may be a polymer such as Parylene.
摘要:
A biocompatible, mechanical, micromachined pressure sensor and methods of manufacturing such a pressure sensor are provided. The pressure sensor of the current invention includes a high-aspect-ratio curved-tube structure fabricated through a one-layer parylene process. The pressure sensor of the current invention requires zero power consumption and indicates the pressure variation by changes of the in situ in-plane motion of the sensor, which can be gauged externally by a direct and convenient optical observation. In one embodiment, the pressure sensor of the current invention has been shown to work as an IOP sensor for eye implantation where the intraocular in-plane motion of the sensor can be recorded from outside of the eye, such that the intraocular pressure in glaucoma patients can be constantly monitored.